1. Field
The present invention relates generally to a wireless communication system, and in particular to a radio receiver that includes a plurality of spatial processing modes. Such a receiver may be part of a transceiver used, for example, in a remote terminal unit of a wireless communication system.
2. Background
Spatial processing using several antennas may be used in virtually any wireless communication receiver, transmitter or transceiver that receives or transmits radio frequency (RF) signals. In the case of a receiver or the receive portion of a transceiver, spatial processing allows processing of the signals received at the antennas. Such receive spatial processing provides for performance improvements over conventional devices that communicate using a single antenna. These improvements include, but are not limited to, improvements in the signal-to-noise ratio (SNR) and the signal-to-interference-plus-noise ratio (SINR) of the received signals, and improvements in the directionality with which signals can be received from a selected device.
Though base stations have often been equipped with, and have benefited from, spatial processing capability, until now, there have been a number of obstacles to implementing spatial processing in remote terminals. For instance, there is an incentive to keep the power consumption of remote terminals low. There also is an incentive to keep the cost of remote terminal units low. Unfortunately, spatial processing typically requires several electronic signal paths, thus relatively high power consumption, and also some computational power. Therefore, the significant increase in cost and power consumption associated with implementing spatial processing in a remote terminal may be prohibitive of such implementation.
Moreover, of the various spatial processing methods known for receiving, it may be difficult to determine which, if any, are particularly suited to a particular remote terminal application or situation. Various spatial processing methods may require different amounts of computation and different amounts of power consumption. Furthermore, some may be applicable to only particular types of signals. Furthermore, different strategies for the spatial processing may be designed to improve or even optimize different factors, and it may be impossible to simultaneously satisfy all desirable properties of the processing.
Therefore, though it would be desirable to benefit from the general performance gains that spatial processing would provide if employed in a remote terminal unit, it would also be desirable to overcome the above-mentioned drawbacks.